Disease-causing microorganisms that have become resistant to drug therapy have increasingly become a public health concern. The mechanism of drug resistance varies with respect to the microorganism and the therapy employed (See generally, Goodman & Gilman's, The Pharmacological Basis of Therapeutics (9th ed. 1996)). For example, strains of Staphylococcus aureus exhibiting resistance to penicillin G appeared shortly after this antibiotic was introduced. The frequency of drug resistance has increased such that over 80% of both hospital- and community-acquired strains of S. aureus are now resistant. Other strains of S. aureus have emerged that are highly resistant to all beta-lactam antibiotics. These organisms, i.e., methicillin-resistant organisms, are prominent in hospitals, in particular, the intensive care unit where there is greater usage of antibiotics. Emergence of antimicrobial resistance has led to increasing challenges in treating illnesses such as tuberculosis, gonorrhea, malaria, and childhood ear infections. As a result of drug resistance to various microorganisms, diseases previously treatable by existing antibiotics may become untreatable, and there may be no adequate antibiotic treatment for newly discovered microbial-related illnesses.
In view of the foregoing, there is a need for new methods of eliminating, reducing or retarding the growth of microorganisms as well as new treatments for the diseases caused thereby.